Processes for carbon-coating a substrate are known and are taught, for example, in U.S. Pat. No. 3,428,519 to Zvanut. Zvanut discloses a process for thermoplastic fiber generation and carbon-coating under atmospheric pressure in an oxygen-rich, closed system.
A second example of Boron-doped carbon-coating is taught in U.S. Pat. No. 3,565,683 to Morelock. Morelock discloses a continuous process for depositing a borocarbon coating on an electrically heated surface of a pyrolytic carbon-coated fused silica fiber as it is passed through a liquid, thermally decomposable boron compound.
U.S. Pat. No. 4,722,860 to Doljack et al. discloses a method for forming a flexible carbon-coated, electrically conductive cloth. An organic compound is pyrolytically coated onto a refractory, fibrous cloth under an inert atmosphere, in a closed system. The use of a vacuum is disclosed as a means for mobilizing organic precursor compounds.
The prior art does not teach or suggest a continuous throughput process for carbon-coating a substrate in an open system, at atmospheric pressure. In particular, an open-system process for semiconductor-doped carbon-coating, under an inert atmosphere, in which the coating occurs by chemical vapor deposition, has not previously been disclosed.